Method of and apparatus for forming thumb receptacles in bowling balls



3,454,440 E'PTACLES July 8, 1969 s. VEZIRAKIS METHOD OF AND APPARATUSFOR FORMING THUMB REC IN BOWLING BALLS Filed Oct. 22, 1965 INVENTOR 575V6 l/EZ/EA 5 5 1 F J: :I. 1

United States Patent METHOD OF AND APPARATUS FOR FORMING THUMBRECEPTACLES IN BOWLING BALLS Steve Vezirakis, Covina, Calih, assignor,by mesne assignments, to Starmaster Trophies, Inc., Portland, Oreg., a

corporation of Oregon Filed Oct. 22, 1965, Ser. No. 500,632 Int. Cl.132% 1/14; A63d 5/00; B32b 31/04 US. Cl. 156242 7 Claims ABSTRACT OF THEDISCLOSURE Finger holes are formed in bowling balls to conform to thefingers of the bowler, by utilizing a cylindrical open ended mold formolding compound, and closing one end of the mold by a pliable patternextending along the mold and conforming to the finger of the bowler. Themolding compound is then poured into the mold and upon hardening forms afinger hole receptacle. The mold is removed by grasping the head of thepattern by the hand until it is smaller than the narrow portion of thefinger cavity formed by the molding compound and drawn from the hardenedmolding compound. The preformed finger receptacle is then inserted in anoversize hole in a bowling ball and centered and aligned with respect tothe hole and bonded to the bowling ball by the use of a pluggingcompound.

Background of the invention Bowling balls have heretofore been drilledto form finger grips for the bowler, the finger holes being sized andspaced to receive the thumb, middle finger and ring finger of the bowlerand to comfortably fit the spread of the bowlers fingers.

The balls many times are not drilled for the hand of a particular bowlerand where the bowler does not have his own ball, he will select a ballin which the hole size and spread approximates the hand of the bowler.

It is, however, difiicult to obtain the exact fit, even where the ballis drilled, for the fingers of the bowler and the finger holes arefrequently too tight or too loose and are cylindrical throughout theirlength and do not provide suificient gripping surface to give theaverage bowler the required control of the ball.

This has been remedied by molding the finger holes of the bowling ballto conform to the fingers of the bowler to increase the finger grippingaction on the ball, with the resultant added comfort to the bowler andincreased control of the ball as in my prior application Ser. No.409,771 filed Nov. 9, 1964 and now Patent No. 3,316,588, dated May 2,1967.

In my said prior application Ser. No. 409,771 now United States PatentNo. 3,316,588 a pattern is inserted in a plastic material, such as aplugging compound poured in an oversized hole in the bowling ball tomold permanent finger holes in the ball conforming to the fingers of thebowler.

In the method of my present application, finger receptacles havinginterior walls conforming to the fingers of the bowler are first moldedwhen outside of the ball and then inserted in plugging compound inoversize holes in the ball and retained in place until hardened.

While both methods of forming finger holes in bowling balls have provedto be very satisfactory, the present 3,454,440 Patented July 8, 1969method is more readily adaptable for small shops and for individualbowlers.

Objects of the invention It is, accordingly, a principal object of thepresent invention to provide a new and improved method of forming fingerholes in bowling balls conforming to the forms of the fingers of thebowler, by inserting in the ball finger receptacles tailored to thefingers of the individual bowler using the ball, and by retaining thereceptacle in the ball by means of an adhesive plastic compound, whichsubsequently hardens to permanently bond the receptacle in the ball.

Another object of the invention is to provide a new and improved methodof conforming the thumb hole in a bowling ball to the general form andsize of the thumb of the bowler, by providing a thumb receptacletailored to the thumb of the bowler and by bonding the thumb receptacleto an enlarged thumb hole in the bowling ball.

Still another object of the invention is to improve upon the bowlingballs heretofore in use by molding individual receptacles conforming tothe fingers of the bowler and having generally cylindrical exteriorwalls, by locating these receptacles at the proper angles for thefingers of the bowler and bonding the receptacle so located to oversizedholes in the bowling ball.

Still another object of the invention is to provide an improved methodof forming the finger holes in bowling balls to conform to the fingersof the bowler, in which finger receptacles are molded from a compounddifferent from the material from which the ball is made, but which willbond to the ball, and are placed in oversized finger holes in thebowling ball and bonded thereto by a conventional form of compoundcommonly used to repair bowling balls.

These and other objects of the invention will appear from time to timeas the following specification proceeds and with reference to theaccompanying drawings where- FIGURE 1 is a generally diagrammatic viewof a bowling ball;

FIGURE 2 is a sectional view of a finger receptacle constructed inaccordance with the principles of the present invention with the upperpart of the receptacle shown in elevation;

FIGURE 3 is a cross sectional view of a container to a plastic moldingcompound showing a pattern in the container in solid and illustratingthe operation of molding the receptacle shown in FIGURE 2;

FIGURE 4 is a cross sectional view taken through a fragment of a bowlingball through the thumb hole thereof and showing the oversize hole to bedrilled in the ball in dotted line, in order to show a step in themethod of the invention;

FIGURE 5 is a fragmentary cross sectional view of a bowling ball takenthrough the thumb hole of the ball showing the opening in the holeenlarged to trim the previous hole in the ball;

FIGURE 6 is a partial fragmentary cross sectional view taken through thethumb hole of a bowling ball illustrating a further step in insertingthe receptacle in the thumb hole of a bowling ball;

FIGURE 7 is a cross sectional view taken through the thumb hole of abowling ball illustrating a still further step in the operation ofbonding the receptacle to the thumb hole of a bowling ball; and

FIGURE 8 is a partial fragmentary cross sectional view taken through thethumb hole of a bowling ball showing the receptacle bonded in positionin the hole and trimmed flush with the periphery of the ball.

In the embodiment of the invention illustrated in the drawings, I haveshown in FIGURE 2 a thumb receptacle or insert 10 which is adapted to bebonded to the thumb hole of a bowling ball in accordance with theprinciples of the present invention, to form a gripping receptacle inthe ball, conforming substantially to the thumb of the individualbowler. The receptacle 10 may be made from a conventional compound, suchas is commonly used to plug the holes in bowling balls. A commoncompound is an epoxy compound which rigidities upon setting and is knownto the bowling ball repair trade as Ball Plug. Another suitable compoundwhich may be used is a similar epoxy compound known to the trade as BallMate.

The receptacle 10 may be molded by placing a pattern 11 within an opencylindrical retainer or mold 12, with an enlarged head 13 of the patternplugging the bottom of the retainer or mold and retaining the moldingcompound thereto to form the thumb receptacle or insert 10.

The pattern 11 may be made to conform to the finger of the individualbowler and is preferably made from a flexible material which willstretch or contract and reduce in cross sectional area upon the exertionof a pulling force thereon. The pattern 11 may be like the pattern shownand described in my before mentioned application Ser. No. 409,771 filedNov. 9, 1964, now United States Patent No. 3,316,588 and entitledPliable Molding Tool and as shown in FIGURE 3 of the drawings, the head13 of the pattern is generally cylindrical and slightly larger than theinside diameter of the cylindrical mold 12, to seal the bottom of saidmold when the pattern and head moves into the mold. The pattern 11 has areduced diameter stem or finger portion 14 extending from the head 13and generally conforming to the contour of the finger. The fingerportion 14 has a reduced diameter generally cylindrical wall portion 15extending from the head for a portion of the length of the pattern andhas a shallow fiat concave recess 15a on one side thereof locking thepattern to the molding compound upon hardening of the molding compound.A ridge 15b at the inner end of the recess converges into an inwardlycurved convex portion 150 in the general form of the end of the fingerbehind the nail. The cylindrical wall portion also has an oppositeflattened portion 152 generally simulating the nail portion of thethumb. While the pattern may be made from any suitable pliable orflexible material, a silicone rubber is a preferred material. When themolding compound poured about the pattern 11 hardens, which requires aperiod of from three to four hours, the pattern is removed by grippingthe head 13 thereof and contracting the pattern to readily be withdrawnfrom the newly molded receptacle, and forming a receptacle having athumb shaped cavity 15 therein.

A large number of receptacles 10 may be molded in this manner in varioussizes and lengths and may be graduated into sixty-fourths of an inch toenable a receptacle to be selected in advance, which will fit the thumbof the individual bowler regardless of the size of the thumb of thebowler. The receptacles or inserts, however, may all be of approximatelythe same outside diameter.

In FIGURE 1, I have diagrammatically shown a bowling ball 16 having athumb hole 17 and finger holes 18, 18. The thumb and finger holes aredrilled in a drill press by setting the ball in a fixture and drillingthe holes to a required pitch, as determined by a gauge for the fixtureand drill press (not shown). Where the gauge may be set to zero, fordrilling a thumb hole, the hole is a radial hole and its center willintersect the center of the ball. The finger holes are usually drilledwith a forward pitch, a three-eight inch forward pitch being a standardangle. With such a pitch the centers of the finger holes intersectradial lines at distances of three-eighths inches from the center of theball. The pitches of the thumb and finger holes, of course, may bereverse pitches as well as forward pitches, and may even be sidepitches, in accordance with the size and shape of the bowlers hand, andthe grip required to provide a perfectly balanced grip of the bowler onthe ball.

In determining the angle of insertion of the receptacle in the thumbhole of a bowling ball, the bowler is given a predrilled ball. Thebowlers thumb may then be inserted in the thumb hole of the ball andslowly drawn out of the thumb hole, to determined the angle at which thebowler has a balanced grip on the ball. This angle of the thumb holewill usually angle to the bowlers palm or ring finger. Two parallellines 20, 20 may be then drawn on the surface of a ball as a visualguide, to determine the angle at which the receptacle is to be inserted.

Upon the selection of a receptacle of the proper size and determiningthe angle at which the receptacle is to be inserted, the length of thebowlers thumb is measured from the bottom of the cavity of the insertand this length is marked on the outside of the insert to determine thedepth at which the insert is to be inserted in the bowling ball and thedepth of the thumb hole to be drilled in the ball.

The ball 16 may then be centered on the drill press with the same sizebit as the diameter of the receptacle that is to be installed in theball. With the ball centered and the angle of the drill with respect tothe ball located to give the proper pitch to the thumb hole, the ballmay then be clamped on its ball hloder (not shown) to solidly positionthe ball with respect to the drill press.

Upon centering the ball and drilling a centering hole therein of thesize of the receptacle, the centering bit is 'then removed and a largerbit larger in diameter than the outside diameter of the receptacle isplaced in the chuck and the hole is redrilled to this larger diameter tothe desired depth marked on the insert, as designated by the brokenlines indicated by reference character 19 on FIG- URE 4.

All existing round edges or bevels around the hole of the ball may thenbe cut out. In order to do this a counterdrill hole 21 of an enlargeddiameter than the previously drilled hole, may preferably be drilled inthe ball in centered relation with respect to the previously drilledhole and for a short portion of the depth thereof. This counterdrill notonly cuts out all previous round edges or bevels around the thumb holeof the ball but also provides room for pouring a bonding compound, forbonding the receptacle to the ball, into the drilled hole.

A plugging clay indicated by reference character 23 may then be placedaround the counterdrilled hole in the ball (FIGU-RE 6) in accordancewith conventional practice in plugging the hole of a bowling ball.

The hole may then be filled with a plugging compound about one-fourthfull, as indicated by reference character 25 in FIGURE 6. This materialmay be the same compound from which the receptacle is molded and maypreferably be a material known to the trade as Ball Plug, although othercommercial materials may be used with satisfactory results.

With the hole partially filled with plugging compound, the insert 10 maythen be placed in the hole in the bowling ball at the proper angle, byfollowing the previously made guide marks 20 on the outside of the ball,indicating the pitch angle of the receptacle or insert. The receptaclemay then be inserted all the way to the bottom of the ball, so as toassure a thumb hole of the proper length. This also eliminates airpockets at the bottom of the hole.

If the plugging compound should not entirely fill the hole, additionalcompound may be poured in the hole to entirely fill the hole andpermanently hold the receptacle in place.

With the receptacle inserted in the thumb hole at the proper angle, tothe bottom of the hole, and the thumb hole completely filled withcompound, a piece of masking tape 26 may be placed over the top of theinsert and adhesively secured to the surface of the ball on oppositesides of the receptacle, to assure a steady position of the insert andto prevent the insert from raising up from the bottom of the hole.

The plugging compound may then be allowed to harden which requires aperiod of from three to four hours at room temperature.

Upon the hardening of the plugging compound, the 1 plugging clay, excessplugging material and receptacle may be removed from the ball to bringthe level of the insert or receptacle flush with the top of the ball.The hole in the receptacle may then be beveled if desired by the use ofa file and sander and the beveled area may be finished with fine emerypaper and then rubbed by the use of rubbing compound or jewelers rouge.

A thumb hole has thus been provided in a bowling ball generallyconforming to the thumb of a bowler and pitched at the proper angle toenable balancing of the ball upon release from the thumb of the bowler.If desired, finger receptacles may be mounted in the bowling ball in thesame manner as the thumb receptacle, although it has been found thatwhere the thumb hole is proper and fits the thumb of the bowler and isat the proper pitch, that it is not usually necessary to conform thefinger holes to the fingers of the bowler, Where the finger holes areproperly spaced and pitched.

The thumb hole forms an integral part of the ball, being bonded theretoby the plugging compound, and cannot be distinguished from the materialfrom which the ball is made upon proper finish of the ball.

While I have herein shown and described one form in which the inventionmay be embodied, it may be understood that various variations andmodifications in the invention may be attained without departing fromthe spirit and scope of the novel concepts thereof.

I claim as my invention:

1. A method of forming a thumb hole in a bowling ball comprising thesteps of:

providing a finger receptacle having a cavity therein formed togenerally conform to the finger of an individual bowler,

centering the ball by drilling a hole in the ball of the diameter of theoutside diameter of the receptacle at a selected release angle withrespect to the axis of the ball,

enlarging the initial hole by drilling a hole in the ball of a argerdiameter than the diemeter of the finger insert and coaxial with theaxis of the first hole and drilled to a depth determined by the lengthof the thumb of the bowler,

filling the hole with a plugging compound for a portion of the depththereof,

inserting the receptacle into the hole and the plugging compoundtherein, to the bottom of the hole,

then allowing the plugging compound to harden and cleaning excessplugging compound and the projecting part of the insert from the hole.

2. A method of forming a finger hole in a bowling ball comprising thesteps of:

providing a finger receptacle having a cavity generally conforming tothe thumb of the bowler,

determining the release angle of the thumb of the bowler,

marking this angle on the surface of the ball,

marking the length of the bowlers thumb from the bottom of thereceptacle on the outside wall of the receptacle,

centering the ball by drilling a hole in the ball, of the diameter ofthe receptacle, at the proper release angle for the bowler,

enlarging the centering hole by drilling a coaxial hole of a largerdiameter than the outside diameter of the insert,

partially filling the hole with plugging compound,

placing plugging clay around the hole,

placing the receptace in the hole to the bottom thereof,

and retaining the receptacle in position in the hole unil hardening ofthe plugging compound and then cleaning excess compound and theprojecting end portion of the receptacle flush with the surface of theball.

3. A method of forming a finger hole in a bowling ball in accordancewith claim 2,

wherein the receptacle is retained to the hole until hardening of theplugging compound by placing adhesive tape over the top of thereceptacle and adhesively secured to the surface of the ball.

4. A method of forming a finger hole in a bowling ball in accordancewith claim 3,

wherein the receptacle is molded from an epoxy compound and the pluggingcompound is a compound similar to the compound forming the receptacle.

5. A method of forming a finger hole in a bowling ball comprising thesteps of:

providing a finger receptacle having a cavity generally conforming tothe thumb of a bowler and longer than the thumb of the bowler,

determining the release angle of the thumb of the bowler and markingthis angle on the surface of the ball,

marking the length of the thumb on the receptacle measured from thebottom of the receptacle toward the open end thereof,

centering the ball on a drilling fixture,

drilling a hole in the ball of the diameter of the outside diameter ofthe receptacle at the release angle marked on the ball,

enlarging the previously drilled hole by drilling, and

drilling to a depth equal to the length of the thumb of the bowler,

trimming and enlarging the hole at the entering end thereof by drillingan enlarged diameter counterdrilled hole for a short portion of thelength of the drilled hole,

placing plugging clay around the hole,

partially filling the hole with plugging compound,

placing the receptacle in the hole to the bottom thereof at the properangle determined by the release angle guide lines marked on the surfaceof the ball,

taping the receptacle to the ball by placing adhesive tape over the topthereof and then cleaning the portion of the receptacle and pluggingcompound projecting above the surface of the ball flush with the surfaceof the ball.

6. A method of forming a finger hole in a bowling ball in accordancewith claim 5,

wherein the receptacle and plugging compound are an epoxy resincompound.

7. An apparatus for forming preformed finger hole receptacles forbowling balls for bonding to a predrilled hole in a bowling ball, saidapparatus being in combination with an elongated open ended cylindricalmold longer than the length of the finger,

a pliable finger pattern having a generally cylindrical head conformingto and sealing an end of said mold, and having a body portion extendingfrom said head conforming generally to the form of the finger, said bodyportion including a reduced diameter generally cylindrical wall portionextending from said head for a portion of the length of said pattern andhaving a shallow flat concave recess on one side thereof, locking thepattern to the molding compound upon hardening of the molding compoundpoured into said mold,

a ridge at the inner end of said recess, converging toward the oppositeend of said pattern from saidhead into a flattened inwardly curvedconvex portion in the general form of the end of the finger behind thenail,

said cylindrical wall portion having an opposite flattened portiongenerally simulat- 'ing the nail portion of the finger,

and said head besides forming a seal for the 1 bottom end of the moldbeing adapted to be gripped by the hand to stretch and unlock thepattern for removal from its mold.

8 References Cited UNITED STATES PATENTS 2,777,693 1/1957 Mitchell273-63 3,113,775 12/1963 Taylor 273-63 5 3,129,002 4/ 1964 Bednash273-63 3,157,912 11/1964 Lisczawka 185.1 3,239,223 3/1966 Mason 273-63 0HAROLD ANSHER, Primary Examiner.

US. Cl. X.R. 18-5.1; l5698, 252, 293; 273-64

